1. Field of the Invention
This invention relates generally to froth flotation collectors and froth flotation processes for using the same for the beneficiation and recovery of metal values such as copper, lead, zinc, nickel, molybdenum, gold, silver and platinum group metals (PGM), which include platinum and palladium metals, from mineral ore bodies. More particularly, it relates to processes that employ sulfide mineral collectors comprising certain dithiocarbamate compounds which exhibit excellent metallurgical performance over a broad range of pH values.
2. Description of the Related Art
Froth flotation is a widely used process for beneficiating ores containing value minerals. A typical froth flotation process involves intermixing an aqueous slurry, which contains finely ground ore particles, with a frothing or foaming agent to produce a froth. The ore particles that contain a desired mineral are preferentially attracted to the froth due to an affinity between the froth and the exposed mineral on the surfaces of the ore particles. The resulting beneficiated minerals are then collected by separating them from the froth.
Chemical reagents known as “collectors” are commonly added to the slurry to increase the selectivity and efficiency of the separation process. U.S. Pat. Nos. 4,584,097, 6,732,867, 6,820,746, 6,988,623, and 7,011,216, which are hereby incorporated herein by reference in their entireties, disclose the use of N-alkoxycarbonyl-O-alkylthionocarbamates as collectors.
Froth flotation is especially useful for separating finely ground value minerals from their associated gangue or for separating value minerals from one another. Because of the large scale on which mining operations are typically conducted, and the large difference in value between the desired mineral and the associated gangue, even relatively small increases in separation efficiency provide substantial gains in productivity.
There is an ongoing need for improved collectors and methods of using them for the recovery of metals from ores.